Section 400.620  Alternative Requirements for Historic Buildings

The following alternative requirements may be substituted for the requirements of Section 400.310 when a historic building undergoes alterations:

a)         Changes of level may be accommodated by ramps having the following maximum slopes:

1)         A slope between 1:10 and 1:12 is allowed for a maximum rise of 6 in.

2)         A slope between 1:8 and 1:10 is allowed for a maximum rise of 3 in. (ADAAG 4.1.6(3)(a))

3)         A slope between 1:6 and 1:8 is allowed for a maximum rise of 2 in.

4)         Where access to any space in a historic building will be limited to controlled groups with assigned tour guides, changes in level as provided in this subsection (a)(1) may be accommodated by means of a detachable ramp.

b)         Where access to any space in a historic building will be limited to controlled groups with assigned tour guides, requirements of the following Sections are waived for that space:

1)         Section 400.310(j), Doors, except minimum widths as noted in subsection (a)(5), below, and threshold heights;

2)         Section 400.310(p), Storage;

3)         Section 400.310(r), Controls and Operating Mechanisms, where not intended to be operated by the general public;

4)         Section 400.310(t), Detectable Warnings; and

5)         Section 400.310(u), Signage.

c)         Where access to any space in a historic building will be limited to controlled groups with assigned tour guides, or where a full-time door attendant or concierge is provided at the door within visual and audible communication range, there are no special requirements for door hardware or operation.

d)         Door hardware.  The addition of adapter lever handles that retain the existing hardware will be considered to meet the Secretary of the Interior's Standards as they do not result in the removal of any historic features from the structure.

e)         Minimum clear door opening width for a single door or the single active leaf of a pair of doors shall meet the requirements of Section 400.310(j)(4). When the alteration of an existing historic door does not meet the Secretary of the Interior's Standards, a lesser dimension may be considered to be accessible if it provides the highest level of access within the limited dimensions available. (ADAAG 4.13.5)  Examples of acceptable methods of providing improved access while maintaining the historic door include:

1)         Maintain the door opening area free of any obstructions so that the clear opening can be measured with the door in a 180 degree position rather than the 90 degree position.

2)         Reverse the swing of the door.

3)         Remove or alter the side door stop(s).

4)         Replace the existing hinges with offset hinges.

            Example:  The main entrance door on a 19^th century structure used as a house museum is entered from a porch that is otherwise accessible, but the door is only 30 in. wide.  Because the door, associated transom and surrounding trim are all significant features of the building, altering the opening and replacing the door does not meet the Secretary of the Interior's Standards. The installation of off-set hinges and the replacement of the door stops creates a clear opening of 29½ in., but otherwise retains all of the historic features of the house.  In these circumstances, the modified front entry door would be considered to be accessible.

f)          For paired doors where an individual leaf does not provide the minimum clear opening, the following options provide improved access:

1)         Activating the second leaf; or

2)         Adding a power operator that activates both leaves.

g)         If it is determined that no entrance used by the public can comply with Section 400.310(k) without threatening or destroying the historic character of the building or facility, then access at any entrance not used by the general public, but open (unlocked) with directional signage at the primary entrance may be used.  The accessible entrance shall also have a notification system. Where security is a problem, remote monitoring may be used. (ADAAG 4.1.7(3)(B) Exception)

h)         Accessible routes from an accessible entrance to all publicly used spaces on at least the level of the accessible entrance shall be provided.  Access shall be provided to all levels of a building or facility in compliance with Section 400.310(a) whenever practical, and where such access would not threaten or destroy the historic character of the building or facility. (ADAAG 4.1.7(3)(d))

i)          Where the historic aspects of the building or facility would be destroyed, or so greatly altered as to have an adverse effect on a historic stair, the requirements of Section 400.310(f) are waived.